<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Upload</title>
</head>
<body>
    <div>
        <input type="file" name="file" onchange="uploadFile(this);">
    </div>
    <div>
        <pre id="ret-content"></pre>
    </div>
    <script>
        function uploadFile(t){
            if(t.files.length<=0) return;

            let fm=new FormData;
            fm.append('image',t.files[0]);

            fetch('upload',{
                method:'POST',
                body:fm
            })
            .then(res=>{
                return res.text();
            })
            .then(text=>{
                let d = document.getElementById('ret-content');
                d.innerHTML = `<img src = "/image/${text}" `
                                + ` style = "width:80%; height:auto;">`;
            });

        }
    </script>
</body>
</html>